Various laser machining devices are used to micro-machine patterns in substrates. Such systems typically are used in the manufacture of electrical circuit boards. Electrical circuit board manufacture comprises depositing conductive elements, such as conductive lines and pads, on a non-conductive, typically dielectric, substrate. Several such substrates are adhered together to form an electrical circuit board. In order to provide electrical interconnection between the various layers of an electrical circuit board, holes, called vias, are drilled through selected substrate layers and plated with a conductor. Electrical circuit boards typically include tens of thousands of vias, and as many as several hundred thousand vias.